Mabulatrichus kumayaensis, Nakamura & Fukumori & Fujikawa, 2010

Nakamura, Y. - N., Fukumori, S. & Fujikawa, T., 2010, Oribatid Fauna (Acari, Oribatida) From The Kumaya Cave Of Iheya Village In Central Ryukyu Arc, South Japan, With A Description Of Several New Species, Acarologia 50 (4), pp. 439-477 : 457-461

Mabulatrichus kumayaensis sp. nov.

[Japanese name: Kumaya-nokomedani] ( Figs. 12 , 13 and 14 )

Diagnosis — Body length 414 µm; width 229 µm. Numerous notogastral micropores. Rostrum dentate at anterior margin; seven dens small, rounded. Humeral saccule (hu) large. Piriform organ (py) conspicuous. Ten pairs of notogastral setae. Notogaster with marginal line between anterior of setae la. Epimeral setal formula 3-1-3-3. Trochanter IV bearing seta. Heterotridactylous.

Material examined — Holotype (Female) (NSMT-Ac 13594) from point B.

Etymology — After the name of sampling point, Kumaya Cave.

Measurements and body appearance — Body length 414 µm; width 229 µm. Body colour light brown. Whole integument smooth, with numerous notogastral micropores.

Prodorsum — Rostrum dentate at anterior margin; seven dens small, rounded ( Fig. 12A ). A pair of longitudinal ridges convergent, running from bothridia to anterior of setae le. Setae ro (48 µm), le (89 µm) and in (59 µm) spiniform, ciliate throughout length, originating from small apophyses. Bothridia opened antero-laterally. Sensilli (ss) (64 µm) setiform, ciliate throughout length; relative lengths ss ≈ 1.3x ro. Setae ex (15 µm) thin, short, smooth, setiform.

Notogaster — Medially interrupted dorsosejugal scissure directed forwards, ending at level of mid-distance between setae le and in. Humeral region developed, bearing barbed spiniform setae c 2 (36 µm). Humeral saccule (hu) large. Piriform organ (py) conspicuous ( Fig. 12B ). Other nine pairs of notogastral setae except for c 2, thin, smooth, short setiform (8 µm). Lyrifissures ia (16 µm) and im (18 µm) remarkable long, aligned almost perpendicular to notogastral outline; ih and ip transversly aligned; ips obliquely aligned to notogastral outline. Notogaster with marginal line between anterior of setae la ( Fig. 12C ). Notogaster separated medially and overlapping at posterior border ( Fig. 14 ).

Ventral region — Genital aperture (41 µm) almost square in form; anal aperture (69 µm) rectangular; distance (99 µm) between them about 2.4x and 1.4x as long as lengths of genital and anal apertures, respectively. Genito-anal setal formula 4-1-1- 2; all setae smooth, setiform; genital setae (15 µm) about 4x longer than anal (3 µm) and adanal (3 µm) setae, and about 2.5x longer than aggenital setae (6 µm). Setae an 1 and ad 3 absent. Genital setae (g 1) inserted at anterior margines of plates; the others inserted at the mid-ventral line. Setae ag inserted almost at level of posterior margin of genital aperture. Setae ad 1 aligned in postanal position, ad 2 in adanal. Lyrifissures iad located postero-laterally to anterior margin of anal aperture. Sternal ridge and epimeral borders indistinct. Epimeral setal formula 3-1-3-3; setae roughened setiform. Diarthric subcapitulum bearing 3 pairs of setae: a (25 µm), m (35 µm) and h (35 µm); setae barbed; a and m setiform; h spiniform. Custodium sharp, long, extending anteriorly of setae 1 c ( Fig. 13A ).

Legs — Heterotridactylous; median claw inflexed, shorter than lateral ones. Setal formula: I (1-5-2-4-16), II (1-5-2-4-14), III (2-3-1-3-11), IV (1-2- 2-3-10). On tarsus I, famulus ε minute bacilliform, situated lateral to seta ft ’ ( Fig. 13B ). Solenidion ω 1 bacilliform, inserted posterior to famulus. Solenidion ω 1 setiform, situated anterior to ft ’. Solenidion ’ 1 on tibia I originating from apophysis; ’ 2 situated lateral to the base of apophysis of ’ 1.

Remarks — The new species is distinguished from all the species of the genus Mabulatrichus , especially from M. baloghi ( Mahunka, 1993) by the absence of two large incisions between medial and lateral teeth, from M. dentatus Coetzee, 1993 by the obsence of a long epimeral setae la, from M. litoralis Aoki and Hirauchi, 2000 by the presence of rostral dens, conspicuous piriform organ, long dorsoseju-

Acarologia 50(4): 439–477 (2010)

gal scissure, and trochanter IV bearing seta v, and from M. iranicus Akrami and Coetzee, 2007 by having round rostral dens and conspicuous piriform organ.

Figures

FIGURE 12: Mabulatrichus kumayaensis sp. nov. A, Prodorsum; B, Anterior half of left notogaster; C, Posterior half of left notogaster.

FIGURE 13: Mabulatrichus kumayaensis sp. nov. A, Anterior half of ventral region; B, Solenidial region on tarsus and tibia of leg I.

FIGURE 14: Mabulatrichus kumayaensis sp. nov. Posterior half of ventral region.